Fix package resolution in Node.js 17+ for support/4.x

.github/workflows/tests.yml

@@ -198,6 +198,55 @@ jobs:
       - name: Run verify task
         run: ${{ matrix.task.run }}
 
+  package:
+    name: Export ${{ matrix.conditions }}, Node.js ${{ matrix.node-version }}
+    runs-on: ${{ github.event.inputs.runner || 'ubuntu-latest' }}
+    needs: [install]
+
+    # Skip when scheduled or run manually
+    if: ${{ !inputs.runner }}
+
+    strategy:
+      fail-fast: false
+
+      matrix:
+        node-version:
+          - 12.18 # Node.js 12.18 uses package exports with trailing slashes
+          - 12 # But Node.js 12.20+ uses package exports with subpath patterns
+          - 18
+
+        conditions:
+          - require
+          - import
+
+        exclude:
+          - conditions: import
+            node-version: 12.18
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Restore dependencies
+        uses: ./.github/workflows/actions/install-node
+
+      - name: Change Node.js version
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+
+      - name: Export ${{ matrix.conditions }}, Node.js ${{ matrix.node-version }}
+        env:
+          # Node.js conditions override from "require" to "import" etc
+          # https://nodejs.org/api/cli.html#-c-condition---conditionscondition
+          FLAGS: ${{ matrix.conditions != 'require' && format(' --conditions {0}', matrix.conditions) || '' }}
+
+        run: |
+          node --eval "console.log(require.resolve('govuk-frontend'))"${{ env.FLAGS }}
+          node --eval "console.log(require.resolve('govuk-frontend/package.json'))"${{ env.FLAGS }}
+          node --eval "console.log(require.resolve('govuk-frontend/govuk/i18n.js'))"${{ env.FLAGS }}
+          node --eval "console.log(require.resolve('govuk-frontend/govuk-esm/i18n.mjs'))"${{ env.FLAGS }}
+
   regression:
     name: Percy
     needs: [install, build]

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 ## Unreleased
 
+### Fixes
+
+We’ve made fixes to GOV.UK Frontend in the following pull requests:
+
+- [#3817: Fix package resolution in Node.js 17+](https://github.com/alphagov/govuk-frontend/pull/3817)
+
 ## 4.6.0 (Feature release)
 
 ### New features

package/package.json

@@ -4,20 +4,22 @@
   "version": "4.6.0",
   "main": "govuk/all.js",
   "module": "govuk-esm/all.mjs",
+  "sass": "govuk/all.scss",
   "exports": {
     ".": {
       "sass": "./govuk/all.scss",
       "import": "./govuk-esm/all.mjs",
       "require": "./govuk/all.js"
     },
     "./govuk/": "./govuk/",
+    "./govuk/*": "./govuk/*",
     "./govuk-esm/": "./govuk-esm/",
+    "./govuk-esm/*": "./govuk-esm/*",
     "./package.json": "./package.json"
   },
   "sideEffects": [
     "govuk-esm/vendor/**"
   ],
-  "sass": "govuk/all.scss",
   "engines": {
     "node": ">= 4.2.0"
   },